For nearly 20 years Sony in Japan has been plagued by the myth of the "Sony Timer" – but is there really a kill-switch that destroys your device just after its warranty runs out? Many Japanese genuinely believe that there is.

It was the recall of more than 4.1 million Dell laptops containing faulty Sony batteries in 2006 that jump-started a rumour that has been around for decades. From 1980 to 2006 geeks and tech-obsessed Japanese had joked about the existence of the timer, creating sarcastic manga and venting anger through online forums. But the Dell recall launched the urban legend into the public eye and angry Sony sufferers jumped at the chance to denounce the company.

The mass spontaneous combustion of those batteries damaged Sony’s reputation in Japan enormously. For a nation proud of their technological innovations, burning laptops and the biggest product recall in history were not exactly easy to deal with. Since then rumours have continued to fly across the internet about the existence of the timers. Sony itself is well aware of the urban legend – its current Vice Chairman Ryoji Chubachi mentioned it in public back in 2007.

But a Sony executive in 2006 had already stirred rumours when he mentioned the timers in a talk at a major technology event. He insisted that it was totally absurd and explained that the company was making every effort to dispel the myth.

Their campaign clearly isn’t going that well: the phrase has now become so common that Sony products are often avoided in Japan due to a genuine belief that they just don't last. The Playstation 3 still remains highly popular as it is allegedly exempt from the timers’ curse, but VAIO laptops, particularly among younger Japanese, are purchased with some hesitation.

Many people believe Sony products last just long enough for the company to bring out a replacement generation. Rumours have even emerged recently that the timers are controlled remotely by the company and set off just when a new laptop is due out. Google searches in Japan add fuel to this fire with VAIO laptop breakages increasing around a year after their release. In fact a google search on the subject will return more than half a million Japanese related hits.

Of course, the "Sony Timer" has never been proved and there’s no evidence that it’s anything other than a Japanese urban legend. But things got pretty interesting when it was revealed that a bug in selected E-Series Bravia TVs meant they’d only last 1,200 hours, before refusing to power on or off. This conveniently adds up to about 3 hours watching per day for one year, the exact period of the television’s warranty. Sony issued a software patch to fix the problem.

Of course, the company is extremely keen to keep this rumour out of Europe, an area where its products’ reputation is still justifiably very good. But the legend is spreading across the internet, with Western tech forums being slowly flooded with horror stories of products breaking soon after warranties expire.

Even so, you probably don’t need to rush out to renew your VAIO's warranty.